The city of San Bernardino, California, occupies much of the San Bernardino Valley, which indigenous tribespeople originally referred to as "The Valley of the Cupped Hand of God". The Tongva Indians also called the San Bernardino area Wa'aach in their language.^{[self-published source?]} Upon seeing the immense geological arrowhead-shaped rock formation on the side of the San Bernardino Mountains, they found the hot and cold springs to which the "arrowhead" seemed to point.

Politana was the first Spanish settlement in the San Bernardino Valley, named for Bernardino of Siena. Politana was established May 20, 1810, as a mission chapel and supply station by the Mission San Gabriel in the ranchería of the Guachama Indians that lived on the bluff that is now known as Bunker Hill, near Lytle Creek. Two years later the settlement was destroyed by local tribesmen, following powerful earthquakes that shook the region. Several years later, the Serrano and Mountain Cahuilla rebuilt the Politana rancheria, and in 1819 invited the missionaries to return to the valley. They did and established the San Bernardino de Sena Estancia. Serrano and Cahuilla people inhabited Politana until long after the 1830s decree of secularization and the 1842 inclusion into the Rancho San Bernardino land grant of the José del Carmen Lugo family.^:37–41

The city of San Bernardino is one of the oldest communities in the state of California, and in its present-day location, was not largely settled until 1851, after California became a state. The first Anglo-American colony was established by pioneers associated with The Church of Jesus Christ of Latter-day Saints or Mormons. Following the Mormon colonists' purchase of Rancho San Bernardino, and the establishment of the town of San Bernardino in 1851, San Bernardino County was formed in 1853 from parts of Los Angeles County. Mormons laid out the town based on the "City of Zion" plan which was typical of Mormon urban planning. Cities are typically laid out with North-South, East-West streets in predetermined city block sizes with wide streets. Often cities are laid out with an alphabetical and numerical system typical for Mormon towns, with streets running alphabet letters for North-South streets and numbers for East-West streets. Mormon colonists developed irrigated, commercial farming and lumbering, supplying agricultural produce and lumber throughout Southern California. The city was officially incorporated in 1857. Later that year, most of the colonists were recalled by Brigham Young in 1857 due to the Utah War. Once highly regarded in early California, news of the Mountain Meadows Massacre poisoned attitudes toward the Mormons. Some Mormons would stay in San Bernardino and some later returned from Utah, but a real estate consortium from El Monte and Los Angeles bought most of the lands of the old rancho and of the departing colonists. They sold these lands to new settlers who came to dominate the culture and politics in the county and San Bernardino became a typical American frontier town. Many of the new land owners disliked the sober Mormons, indulging in drinking at saloons now allowed in the town. Disorder, fighting and violence in the vicinity became common, reaching a climax in the 1859 Ainsworth - Gentry Affair.

In 1860 a gold rush began in the mountains nearby with the discovery of gold by William F. Holcomb in Holcomb Valley early 1860. Another strike followed in the upper reach of Lytle Creek. By the 1860s, San Bernardino had also become an important trading hub in Southern California. The city already on the Los Angeles – Salt Lake Road, became the starting point for the Mojave Road from 1858 and Bradshaw Trail from 1862 to the mines along the Colorado River and within the Arizona Territory in the gold rush of 1862-1864.

Near San Bernardino is a naturally formed arrowhead-shaped rock formation on the side of a mountain. It measures 1375 feet by 449 feet. According to the Native American legend regarding the landmark arrowhead, an arrow from Heaven burned the formation onto the mountainside in order to show tribes where they could be healed. During the mid-19th century, "Dr." David Noble Smith claimed that a saint-like being appeared before him and told of a far-off land with exceptional climate and curative waters, marked by a gigantic arrowhead. Smith's search for that unique arrowhead formation began in Texas, and eventually ended at Arrowhead Springs in California in 1857. By 1889, word of the springs, along with the hotel on the site (and a belief in the effect on general health of the water from the springs) had grown considerably. Hotel guests often raved about the crystal-clear water from the cold springs, which prompted Seth Marshall to set up a bottling operation in the hotel's basement. By 1905, water from the cold springs was being shipped to Los Angeles under the newly created "Arrowhead" trademark.

Indigenous people of the San Bernardino Valley and Mountains were collectively identified by Spanish explorers in the 19th century as Serrano, a term meaning highlander. Serrano living near what is now Big Bear Lake were called Yuhaviatam, or "People of the Pines". In 1866, to clear the way for settlers and gold miners, state militia conducted a 32-day campaign slaughtering men, women, and children. Yuhaviatam leader Santos Manuel guided his people from their ancient homeland to a village site in the San Bernardino foothills. The United States government in 1891 established it as a tribal reservation and named it after Santos Manuel.

In 1867, the first Chinese immigrants arrived in San Bernardino.

In 1883, California Southern Railroad established a rail link through San Bernardino between Los Angeles and the rest of the country.

In 1905, the city of San Bernardino passed its first charter.

Norton Air Force Base was established during World War II.

In 1940, Richard and Maurice McDonald founded McDonald's, along with its innovative restaurant concept, in the city.

Inspired by the success of McDonald's, Neal T. Baker founded his first restaurant in 1952, calling it Baker's Burgers. Three years later, Baker added Mexican food to the menu. Burgers were sold at one window and Mexican food at another; he called this the "Twin Kitchen" concept.

In 1980, the Panorama Fire destroyed 284 homes.

San Bernardino won the All-America City award in 1977, but the city subsequently went into a long decline and has only recently begun to recover from the three recessions of the late 20th/early 21st centuries.

In 1994, Norton Air Force Base closed to become San Bernardino International Airport.

In October 2003, another wildfire, the Old Fire, destroyed over 1,000 homes.

In August 2012, San Bernardino filed for Chapter 9 bankruptcy, with more than $1 billion in debt. The move froze the city's payments to creditors, including its pension payments to the California Public Employees Retirement System for nearly a year. Key changes the city made during the bankruptcy process included: outsourcing its fire department to the county and re-writing the city's charter to provide a more clear chain of command. San Bernardino became the largest city at the time to file for a Chapter 9 bankruptcy, superseded by Detroit's filing in July 2013. Following a judge's approval, the city emerged from bankruptcy in February 2017, making it one of the longest municipal bankruptcies in the United States.^{[citation needed]}

On December 2, 2015, a terrorist attack left 14 people dead and 22 seriously injured.

The 2010 United States Census reported that San Bernardino had a population of 209,924. The population density was 3,519.6 people per square mile (1,358.9/km²). The racial makeup of San Bernardino was 95,734 (45.6%) White (19.0% Non-Hispanic White), 31,582 (15.0%) African American, 2,822 (1.3%) Native American, 8,454 (4.0%) Asian, 839 (0.4%) Pacific Islander, 59,827 (28.5%) from other races, and 10,666 (5.1%) from two or more races. Hispanic or Latino of any race were 125,994 persons (60.0%).

The Census reported that 202,599 people (96.5% of the population) lived in households, 3,078 (1.5%) lived in non-institutionalized group quarters, and 4,247 (2.0%) were institutionalized.

There were 59,283 households, out of which 29,675 (50.1%) had children under the age of 18 living in them, 25,700 (43.4%) were opposite-sex married couples living together, 13,518 (22.8%) had a female householder with no husband present, 5,302 (8.9%) had a male householder with no wife present. There were 5,198 (8.8%) unmarried opposite-sex partnerships, and 488 (0.8%) same-sex married couples or partnerships. 11,229 households (18.9%) were made up of individuals, and 4,119 (6.9%) had someone living alone who was 65 years of age or older. The average household size was 3.42. There were 44,520 families (75.1% of all households); the average family size was 3.89.

The population was spread out, with 67,238 people (32.0%) under the age of 18, 26,654 people (12.7%) aged 18 to 24, 56,221 people (26.8%) aged 25 to 44, 43,277 people (20.6%) aged 45 to 64, and 16,534 people (7.9%) who were 65 years of age or older. The median age was 28.5 years. For every 100 females, there were 97.2 males. For every 100 females age 18 and over, there were 94.0 males.

There were 65,401 housing units at an average density of 1,096.5 per square mile (423.4/km²), of which 29,838 (50.3%) were owner-occupied, and 29,445 (49.7%) were occupied by renters. The homeowner vacancy rate was 3.2%; the rental vacancy rate was 9.5%. 102,650 people (48.9% of the population) lived in owner-occupied housing units and 99,949 people (47.6%) lived in rental housing units.

According to the 2010 United States Census, San Bernardino had a median household income of $39,097, with 30.6% of the population living below the federal poverty line.

Western, central, and parts of eastern San Bernardino are home to mixed-ethnic working class populations, of which the Latino and African-American populations comprise the vast majority of the city. Historically, many Latinos, primarily Mexican-Americans and Mexicans, lived on Mount Vernon Avenue on the West Side. Since the 1960s, the Medical Center (formerly known as Muscoy) and Base Line corridors were mostly black, in particular in the east side and west side areas centering on public housing projects Waterman Gardens and the public housing on Medical Center drive. The heart of the Mexican-American community is on the West and Southside of San Bernardino, but is slowly expanding throughout the entire city. San Bernardino's only Jewish congregation moved to Redlands in December 2009. Some Asian Americans live in and around the city of San Bernardino, as in a late 19th-century-era (gone) Chinatown and formerly Japanese-American area in Seccombe Park on the east end of downtown, and a large East-Asian community in North Loma Linda. Others live in nearby Loma Linda to the south across the Santa Ana River. Filipinos are the largest Asian ethnic group in San Bernardino. There is an Italian community in San Bernardino. There is a rapid increase of Guatemalan immigrants in San Bernardino and the Inland Empire. The white population in San Bernardino has declined while the Hispanic and Asian population increased.